ATLANTA – Hundreds of school systems nationwide exhibit suspicious test scores that point to the possibility of cheating, according to an investigation by The Atlanta Journal-Constitution.

The newspaper examined test results for 70,000 public schools and found high concentrations of scores in school systems from coast to coast.

The analysis doesn’t prove cheating. It reveals that scores in hundreds of cities followed a pattern that, in Atlanta, indicated cheating in multiple schools.

The newspaper reported in 2008 and 2009 about statistically improbable jumps in test scores within the 109-school Atlanta Public Schools system. Those reports led to an investigation by Georgia officials, which found that at least 180 principals, teachers and other staff took part in widespread test-tampering in the 50,000-student district.

In Sunday’s editions, the newspaper reports that 196 of the nation’s 3,125 largest school districts had enough suspect test results that the odds of the results occurring naturally were less than 1 in 1,000. For 33 districts nationwide, the odds of their test scores occurring naturally were worse than 1 in 1 million.

Standardized test scores have been at the forefront of national and local efforts to improve schools. Test performance was the centerpiece of the federal No Child Left Behind Act of 2001, which demanded higher classroom accountability.

Tougher teacher evaluations that many states are rolling out place more weight than ever on the tests.

But the Atlanta paper report found that the sweeping policy shifts rely on test results that may be unreliable.

While the federal government requires states to use standardized testing, it does not require educators to screen scores for anomalies or investigate those that turn up.

“If we are going to make important decisions based on test results — and we ought to be doing that — we have to make important decisions about how we are going to ensure their trustworthiness,” said Daria Hall, director of K-12 policy with the nonprofit Education Trust.

“That means districts and states taking ownership of the test security issue in a way that they haven’t to date.”